不同剂量Er元素掺杂PbO_(2)电极的制备表征及其降解磺胺类抗生素

Preparation and characterization of lead dioxide electrode with different doses of rare Earth element Er and its degradation of sulfonamides

本研究利用电沉积法制备PbO_(2)电极,在制备表面活性层时加入不同剂量的稀土元素Er进行改性,得到0%Er-PbO_(2)、0.5%Er-PbO_(2)、1.0%Er-PbO_(2)、2.0%Er-PbO_(2)、4.0%Er-PbO_(2)等5种电极,运用SEM、EDS、XRD、LSV等手段对制备得到的电极进行表征分析。选择磺胺甲基嘧啶为目标污染物,利用制备得到的电极对其进行电化学氧化降解,以液相色谱和COD指标分析降解效果。结果表明,2.0%Er-PbO_(2)电极表面裂缝较少,均匀致密,晶粒尺寸小,仅为39.96 nm。极化曲线表明,2.0%Er-PbO_(2)析氧电位最高,为1.82 V。同时,该电极对磺胺甲基嘧啶的降解效果最佳,矿化率最大,经测试,在电流密度30 mA·cm^(−2),pH=3.0,磺胺甲基嘧啶30 mg·L^(−1),0.2 mol·L^(−1)的Na2SO_(4)作为支持电解质的条件下,3 h后磺胺甲基嘧啶全部去除,6 h后COD去除率达到71.3%。根据磺胺甲基嘧啶降解过程的中间产物的分析,推断了其降解路径。

In the present study,PbO_(2) electrode was prepared by electro deposition.Different doses of rare earth element Er were added into the surfactant catalytic active layer and five kinds PbO_(2) of 0%Er-PbO_(2),0.5%Er-PbO_(2),1%Er-PbO_(2),2%Er-PbO_(2),4%Er-PbO_(2) electrodes were prepared respectively.These electrodes were characterized and analyzed by SEM,EDS,XRD and LSV.Sulfamerazine(SMR)was selected as the target pollutant and the electrochemical oxidation degradation was carried out.Degradation efficiency was analyzed by HPLC and COD.Characteristic results showed that the surface topography of 2%Er-PbO_(2) electrode was more compact and its grain size was smaller than other kinds of PbO_(2),which was only 39.96 nm.The polarization curves showed that 2%Er-PbO_(2) had the highest oxygen evolution Potential(1.82 V).What’s more,SMR degradation achieved the highest efficiency on 2%Er-PbO_(2) electrode.Under the conditions of 30 mA·cm^(−2),pH=3,SMR 30 mg·L^(−1),0.2 mol·L^(−1) Na2SO_(4) as supporting electrolyte,all SMR was removed after 3 h electrolysis,and the COD mineralization efficiency achieved 71.3%after 6 h degradation.According to the analysis of the intermediate products in the degradation process of SMR,its degradation path was deduced.